This invention relates to a burner appliance which includes a burner assembly and a fuel tank which is separate or remote from the burner assembly. More particularly, the invention relates to a fuel tube for connecting the fuel tank and the burner assembly.
Burner appliances such as campstoves generally include a burner assembly for producing a heating flame and a fuel tank for providing fuel to the burner. Some burner appliances have a remote fuel tank which is separated from the burner assembly and which is connected to the burner assembly by a long tube or hose. However, the connecting tube or hose causes difficulty in providing instant lighting of the burner, i.e., generation of vaporized fuel. After the burner is used, residual fuel remains in the tube. On the next lighting, the residual fuel can rush into the burner and cause flooding of the burner or a high yellow flame which can slow the generation of the vaporized fuel. If the tube is disconnected from the burner assembly, residual fuel in the tube can drain from the tube. The draining fuel can be objectionable and can damage food or clothing which is packed with the burner appliance.
Other prior art remote burner appliances used generator preheating for lighting. Alcohol or preheating paste was used to heat the generator. U.S. Pat. Nos. 1,718,473 and 1,858,264 describe an instant lighting feature for short fuel conduits without preheating. However, the structure is not practical for instant lighting for long conduits or tubes where residual fuel remains in the tube.
To minimize fuel surge that can lead to flooding and slow generation on instant lighting, some previous designs used small diameter capillary tubes. However, capillary tubes were fragile and not suitable for the rugged requirements of camping service.
Flow restrictors such as coils have long been used inside of generators which provide vaporized fuel. See, for example, U.S. Pat. No. 1,958,400. However, narrow clearances inside the generator which were required for flow restriction were impractical because carbon build-up inside the generator would quickly block fuel flow.
U.S. Pat. No. 3,900,281 describes a backpacker's stove which includes a burner and a remote fuel tank. However, the connecting tube does not include any flow restrictor, and there is no seal which prevents the tube from draining when the tube is disconnected. Backpacker's stoves which are sold by the owner of U.S. Pat. No. 3,900,281 include a cable in the fuel tube which connects the burner and the fuel tank. It is believed that the cable is intended to reduce the amount of fuel in the tube in order to increase the response of the flame to adjustments of the fuel valve on the tank and to reduce the length of time the flame continues to burn after the valve is shut off. The stove does not have an instant lighting feature.